1. Field of the Invention
The present invention relates to a container for liquids, more particularly to one for accommodating two kinds of liquids separately from each other until the contents are in use.
2. Description of the Related Art
It is a widely used technique in such fields as photographic developers or adhesives to store two kinds of liquids separately from each other for mixing just before use. Recently, such the technique has also become popular in the food industry for maintaining flavor and aroma of individual components.
Japanese Examined Utility Model Publication (Kokoku) No. 53-18138 proposes a container in which a small cup-like plug accommodating one component therein is fit into an upper free opening of a main body accommodating another component. A lid provided with a cutter covers an upper free opening of the plug. In use, the lid is pressed so the cutter breaks a thin bottom wall of the plug, whereby the component in the plug falls into the main body to mix together with it. This container, however, has the drawback in that the assembly of the plug and the lid requires great care due to their delicate structure. This makes automation of the production process difficult. In addition, the plug cannot be removed at once, making dispensing of the content troublesome.
Japanese Examined Utility Model Publication (Kokoku) No. 52-51103 discloses a container similar to the above, in which a cap provided with a cutter is utilized in place of the lid of the abovesaid container. The cap is screwed down around a neck of a main body accommodating a first component and breaks a bottom wall of a plug accommodating a second component. This container has the same drawbacks as stated before.
Japanese Unexamined Utility Model Publication (Kokai) No. 55-7788 discloses a can for coffee in which a top wall is constituted as a double structure having inner and outer plates and the latter is provided with a knife for breaking the inner plate. In use, the outer plate is pressed or struck down toward the inner plate. The knife breaks the latter and an additive contained in a space between the two plates falls down into coffee contained in the can body. Finally, the can is turned upside down and a bottom wall thereof is opened in a usual manner. This can, however, is not used for accommodating a liquid type additive in the space of the top wall due to lack of sealability between the inner and outer plates. Even for powdery or solid type additives, there may be a risk of contamination. Moreover, since the broken opening of the inner plate is small, the coffee mixture tends to remain in the space between the two plates upon pouring.
Japanese Unexamined Utility Model Publication (Kokai) No. 58-21566 proposes a container for two kinds of liquids comprising a cup-like main body for a first liquid and an inverted cup-like lid for a second liquid having an inward projection at a center of a bottom wall thereof. A diaphragm is sealingly provided between the two. Although this container is simple in structure, manufacture is very difficult. The lid and the main body must be joined with the thin diaphragm therebetween while the liquids are contained therein.
Japanese Unexamined Utility Model Publication (Kokai) No. 59-109678 discloses a container comprising a main body for a first liquid and an easy removable lid with a tab. A small cup for a second liquid is attached to an inside surface of the lid. A bottom wall of the small cup has a weakened line along the width thereof formed by a cut reinforced with an adhesive. In use, the lid is raised up in a cantilever manner by the tab, whereby the lid is bent upward and simultaneously the bottom wall of the small cup is broken along the weakened line. This container, however, has a drawback in that a relatively large force is required to cause the breakage of the small cup because it occurs only after the lid is bent.